Specifications:This extender has been re-designed optically and offers excellent performance with compatible EF lenses (same as the Extender EF 1.4x II). Features a new seven-element design, and same weather-resistant design and anti-reflection internal construction as the new EF 1.4x II. The EF 2x II doubles the focal length of any lens it's mounted to, and reduces its effective aperture by two stops. With the EF 2x II, AF is possible with any EOS body if the lens has an f/2.8 or faster maximum aperture, and compatible Image Stabilization lenses maintain the IS feature when used with any current EOS camera.

2 stop loss, but that's part of the deal. Need to manually focus lenses that are not f/2.8 or faster.

I have used this with a 300mm F/4L and 70-200 F2.8L IS II, and there is no noticeable loss of IQ with either lens. I've photographed dragonflies with it on the 300mm and a 100% crop of the eye shows the individual facets clearly defined. Of course manually focusing these shots is difficult, but when I get it right the results are terrific. I have no qualms about using this, I'm never worried that I'm sacrificing IQ for reach.

Nov 30, 2013

JWilsonphotoOfflineBuy and Sell: On

Registered: Jan 16, 2002Location: United StatesPosts: 19272

Review Date: Mar 1, 2012

Recommend? no |
Price paid: Not Indicated
| Rating: 4

Pros:

Makes a very nice paper weight.

Cons:

Disappointing revision of the Series I. Not crisp, regardless of how the photographer stabilizes it. I bought it, shot a series of tests, put the caps back on and I've never used it since.

Mar 1, 2012

retrofocusOfflineImage Upload: Off

Registered: Apr 19, 2007Location: United StatesPosts: 6258

Review Date: Dec 28, 2009

Recommend? yes |
Price paid: Not Indicated
| Rating: 9

Pros:

This is a review about the Mk I version: Excellent and sharp image quality when used together with 100-400 and 70-200 f4 IS, well built

Cons:

Again, only for the Mk I version of this teleconverter: it does not fit to the Canon 1.4x Mk II teleconverter! For stacking, you need definetely both Mk II teleconverter versions.

I recently bought this used Canon 2x teleconverter, Mk I. Unfortunately you can not attach Mk I and Mk II versions of Canon's teleconverters. They don't fit - since the diameter of the protruding lens element of the 1.4x converter II does not fit into the opening of the older 2x teleconverter I! Still even the older Mk I version of the 2x teleconverter yields high-quality and very shapr images in combination with my extended 100-400 lens at an overall focal length of 800 mm. The loss of two stops can be compensated by higher ISO number and/or longer exposure times. I like using the "pin-tape-trick" to be still able to use f5.6.

Optically both teleconverter 2x versions Mk I and II are very similar - I doubt that a difference is noticeable. The Mk II version has weather sealing while the Mk I version doesn't. If you find a used Mk I version of this teleconverter and you don't need to stack teleconverters, go for it!

Dec 28, 2009

Breitling65OfflineImage Upload: Off

Registered: May 31, 2006Location: United StatesPosts: 5265

Review Date: Oct 20, 2009

Recommend? yes |
Price paid: Not Indicated
| Rating: 9

Pros:

Extending telephoto lenses, great IQ results on some long telephotos. Light, not big. Weathersealed.

Cons:

Cost

I would recomend this product for two great lenses I own:

Canon 300mm F2.8L IS
Canon 500mm F4L IS

On both above with tripod shooting static objects results are great. Sure not as without extender but in some cases when you need to double lens focal this thing must be in your bag.

Oct 20, 2009

DoogieHOfflineImage Upload: Off

Registered: Jan 27, 2009Location: United StatesPosts: 925

Review Date: Oct 19, 2009

Recommend? yes |
Price paid: $250.00
| Rating: 9

Pros:

Build, 2x, minimal stop loss, no color loss

Cons:

Price

I snapped this baby on my 70-200 2.8L and pulled the moon in for some great snaps. I had no loss of color and the sharpness was incredible. I can't wait to use on some local wildlife

Oct 19, 2009

jamato8OfflineImage Upload: On

Registered: Dec 23, 2005Location: United StatesPosts: 2728

Review Date: Sep 20, 2009

Recommend? yes |
Price paid: $298.00
| Rating: 10

Pros:

I have the original Canon 2X, which worked well on my 180L but degraded my other lenses too much. The TC 2X II is for me, a big jump in image quality.

Cons:

None.

I couldn't be happier with this converter. I had expectations it would be better than my 2X I but I am getting almost no loss of image quality even wide open on my 200mm f2, which surprises me. The contrast, color saturation and snap are all there. I have zero reservations now in using my 200 as a 400 f4 with a 5 stop IS. Focusing slowed a bit but still remains fast enough for most subjects. Good show on this one Canon.

Sep 20, 2009

genefixerOfflineBuy and Sell: On

Registered: Jan 22, 2007Location: United StatesPosts: 6532

Review Date: Aug 7, 2009

Recommend? yes |
Price paid: $235.00
| Rating: 10

Pros:

Used correctly will work great on a 500 f4 IS lens

Cons:

lose 2 f stops

With my 400 DO IS and 500 f4 IS, I was initially disappointed in the IQ with this 2X TC in comparison to Canon's 1.4X II TC. However, after some advice from a fellow FMer, I am now totally pleased. The trick: Enough light or high enough ISO to allow stopping down the lens to f11 or better. Wide open the results relatively stink!

Doulbes your affective focal length. Works great on my 300/2.8is & 135L, no loss of IQ, speed not a issue. A slight IQ loss wide open on my 70-200/2.8is, still more thank acceptable.

Cons:

2 stop light loss, it is a 2x converter :)

Wow, I must have got a really good tc and deal here. My first 2x has exceed my expectations. My Canon curse has been lifted for some time now . This tc is excellent on my 300 & 135. IQ is great almost like it's not there. There's a slight down grade in IQ on my 70-200 but not much. Overall I'm very happy with this tc, along with the 1.4 I've got extended range covered. Very pleased.

Jarvis

Jun 12, 2009

BadmonoOfflineImage Upload: Off

Registered: Mar 9, 2009Location: United KingdomPosts: 0

Review Date: Mar 19, 2009

Recommend? yes |
Price paid: Not Indicated
| Rating: 10

Pros:

Great to double your lenses focal length
Cheap - easy to use and carry

Cons:

Variable IQ you need to be choosy - It took me 3 attempts to find a good 'un to go with the 400 F2.8 IS

The most difficult and awkward piece of Canon's kit to obtain - get a good one and you won't see any image degradation whatsoever. However a bad one will give you IQ nightmares. I tried 3 different convertors before finding one that matched my money lens [400 f2.8 IS] this combo gives me an 800mm f 5.6 with fast accurate focussing:-)) a birders delight!!
And when stacked with a 1.4x convertor things get even better. however this combination needs a deeper lens hood to retain contrast. I made one up from 5mm Black under carpet foam which works a treat!! and is light and easy to carry in a bag.
Quite simply if you go birding then you need one - just take your time to find the right one for your main money lens and you'll never regret it:-))

Mar 19, 2009

chuboramaOfflineImage Upload: Off

Registered: Jun 18, 2008Location: JapanPosts: 73

Review Date: Jul 6, 2008

Recommend? yes |
Price paid: $213.00
| Rating: 9

Pros:

cheap alternative to buying another lens, versatility, small and light package

Cons:

Adds length to already long (hard to hand hold steadily) lenses; 2 stops down and a slight loss of image quailty

I picked up this teleconverter the day I also bought the 70-200 2.8, both used, from my local camera store. Played with both for about an hour, and was convinced that the image quality was no worse (a bit better actually) than my 100-300 4.5-5.6. For only 200 dollars more, the versatility of being able to have a 400 5.6 sold me.

Great points of this telecon:

1. Light! Small!
2. Gives me the 400mm (640mm on my 30D) when I need it, but allows me to keep my 70-200 2.8 as a stand alone lens.
3. Cheaper than shelling out another 1,600 or for the 100-400 L, or for a long prime.
4. Great image quality when used properly.
5. Weather sealing when used with appropirate lens and body.
6. Matches with all off white L lens :D

Not so great points:

1. Having to deal with two more lens caps (front and rear) when you want to use it.
2. 2 stops down and some loss of image quality - if you want autofocus capability do your research first before posting rants on the forum...
3. Hard to hand hold a long lens together with the telecon.

In summary:

Don't let the "loss of image quality" fool you into thinking this will make your lens soft - it's much more dependant on things such as how steady you can hold your lens, or the inherent sharpness of the original lens. Most people get this lens to make their long lenses even longer - but that means the big lens just bigger, heavier, and more unwieldy. Get your tripod out!! Don't rag on a 250 dollar telecon.

I had my doubts at first, when I was looking at my images zoomed up on my camera, but after seeing them on my computer screen I was blown away. Yes, there is a loss of sharpness compared to the original lens (which is pretty damn sharp!), but you'd have to zoom in pretty far to really notice that, and no one should spend all day zooming into 100 percent crops. Enjoy the photo as it was meant to be seen! You can get great, sharp and clean images with this! Just remember - it's never a substitue for the real thing, so if you want the last word in image quality, be prepared to pay for it (i.e. the next lens up).

Jul 6, 2008

simon_kOfflineImage Upload: Off

Registered: Mar 12, 2007Location: GermanyPosts: 390

Review Date: May 7, 2008

Recommend? yes |
Price paid: Not Indicated
| Rating: 8

Pros:

IQ with 300/2.8, build quality

Cons:

size (almost as big as my 85/1.8), protruding front element - only the special cap will fit

It works excellent with the 300/2.8!
IQ is very good (not brilliant but still much better than the 100-400L at 400mm!)
I guess it needs the very best lenses for this converter to give great results. The 300/2.8 is one of them.

May 7, 2008

svx94Offline[ X ]

Registered: Mar 25, 2005Location: CanadaPosts: 657

Review Date: Mar 18, 2008

Recommend? yes |
Price paid: $270.00
| Rating: 10

Pros:

Great IQ, build

Cons:

I bought it for last Christmas, when I still have the 300/2.8 IS. The combined 600mm reach seems perfect for birding, but I soon found out I am not good at it. But nonetheless, the indoor test shots turned out great. I frankly can't see much difference in IQ with it on the 300/2.8. The AF speed seems fine as well. I guess the lens made the difference rather than the converter. (I heard some report that it slow down the AF, but not much on the 300/2.8).

Although, I am not a pro, I was picky on IQ. But for this converter, I have yet to find any problem.

It Works, It does what it states, and it does it well, not brilliant, but then it is a 2x extender. Works well with the 70-200 f/2.8 IS and can not even notice any softness

Cons:

AF Does not work with the 100-400 IS L USM Lens, which is a real shame, but manual does and the improvement is good, but the lack of AF is a real pain.

I was a bit disappointed that the 100-400mm IS L USM Lens would work with this adapter, but the AF is totally useless with this lens, which is a shame as it was purchased for this in the hope of getting a cheap useful lens for Motorbike Racing Photo's. That aside I have found a VERY good use for this adapter on this lens, Wildlife, and it takes some stunning photo's with the 2x adapter plugged into it.

I have done some tests with the adapter and without, and with the lens set to 100 and then to 400, the 4 resulting images are very crisp, and the quality loss between the 400 and the 800 (400 + 2x Extender) is very minimal.

Is it worth it, Maybe not, for wildlife and still-ish photography, then yes, but compared to the 1.4x it was a bit of a let down, but I am not really complaining about it, and it will be used, especially with the 100-400mm lens, even though I can not use Auto Focus, the reach with this lens is stunning, and like I said before, not that bad, not great, but it is a very cheap 800, that set to 600 works very well.

If you wanted to choose between the two, I would pick the 1.4x, if you can afford both, it is worth the risk, with the 70-200mm f/2.8 IS USM it does work very well and the images at 400 are still better than the 100-400 without the extender, so it is a worth while purchase.

As a side note, and more from a bit of fun, if you want an extender and you are using a 100-400mm lens, then take a look at the Life Size Adapter for the 50mm Macro, and forget what they say about it only working with the 50mm Macro, it works fantasic with the 100-400mm and some others as well.

Apr 4, 2007

jmrasoOfflineImage Upload: Off

Registered: May 25, 2004Location: SpainPosts: 3564

Review Date: Mar 25, 2007

Recommend? yes |
Price paid: Not Indicated
| Rating: 9

Pros:

Very useble, AF works on 1D series

Cons:

Just a little hunting.

With my Canon 300 2.8 IS the image quality is more than useble at 5.6 as long as you keep speeds around 1/1000 and the subject fills the circle of the focussing screen in the 1D series.